As is known in the art of door latching, with reference to FIGS. 1 and 2, typically an electrically-controlled strike 10 is mounted in a door frame 12 and is configured to engage a lockset 14 disposed on or in an edge portion of a door. The lockset may be a mortise-type lockset or a cylindrical-type lockset (a mortise-type lockset is shown). Typically, lockset 14 includes a spring latch 16, and possibly a dead latch 18. In either lockset type, spring latch 16 is reciprocally moveable between an engaged position (extended) so that it can be positioned in a strike cavity 20 defined in a housing 22 of strike 10 to secure the door in a closed state, and a released position, wherein spring latch 16 is permitted to exit strike cavity 20 and to release the door from the closed state and is free to open. Similarly, dead latch 18, which in a cylindrical lockset-type is adjacent the spring latch, is reciprocally moveable between an enabling position (extended) that permits movement of spring latch 16 from its engaged position to the released position and a disabling position (depressed) that prohibits movement of spring latch 16 from its engaged position to its release position. Typically, spring 16 latch is resiliently biased into the engaged position and dead latch 18 is resiliently biased into the enabled position. Strike 10 also may include a keeper 24 rotatably disposed in housing 22 between a locked position to retain spring latch 16 in strike cavity 20 when in the engaged position, and an unlocked position allow for the release of the spring latch from strike 10 and the opening of the door. In a cylindrical-type locket, keeper 24 may operate to retain the dead latch in disabling position when in the locked position.
Whether used in conjunction with a cylindrical-type locket or a mortise-type lockset, when the door is closed and the latch is secured behind the keeper of the strike, a minimal gap between the extended latch and the locked keeper is desirable. If the gap is too large, the door will rattle within the strike cavity when the latch is in the extended position. A gap that is too large can also have a negative effect on the operation and performance of the dead latch in a cylindrical-type locket. In a cylindrical-type locket, the dead latch may be held in its disabling position by the keeper when the keeper is in its locked position. A gap that is too large between the keeper and the spring latch may allow the dead latch to move to the enabling position (extended) behind the keeper thereby allowing the spring latch to be freely moved to the released position and the door to be opened eliminating the functionality and security provided by the dead latch. If a negative gap is present in a preloaded door condition, the spring latch cannot move to the extended position behind the keeper when the door is closed, which prevents the lockset from securing the door in the frame.
Various factors may affect the size of the gap between the spring latch and the keeper after the locket and strike are installed. Initially, a dimensional stack-up between the door and the frame may affect the resulting size of the gap. To address the gap upon installation of the strike, a collection of separate shims having varying thicknesses are typically provided with the strike. Depending upon the resulting gap, a suitable thickness shim is selected, and then fixedly and non-adjustably secured to the inside surface of the keeper. While the use of a shim may be adequate at the time the strike is installed, a large cause of the resulting gap that presents itself over time is due to the door sagging in the door frame and through use of the door over time. As the door components (hinges, keeper surface, etc.) wear, the gap between the keeper and the spring latch increases. It is not uncommon for the extra shims that are provided with the strike to be discarded after initial assembly or lost when needed again following usage wear on the door leaving no easy way to address the gap between the keeper and the spring latch.
What is needed in the art is an electric strike that allows for offloading a preload pressure on the locket caused by a preloaded door condition, reduction of a gap between the keeper and the lockset to minimize excess movement or rattle in the door, ensures that a dead latch of the lockset does not extend to a fully extended position behind the keeper to render the door unsecure, and allows the gap to be easily adjustable based on the condition of the door for the life of the electric strike. The present invention addresses the above-referenced needs as well as other needs.